One of the most critical actions in studying transportation system impacts on ecosystems and ecological processes is raw data collection, from instruments and observations by people. For a few parameters, this data collection will be through formal measuring systems. For many, and especially for environmental processes and attributes, there may be few government programs operated to understand transportation interactions with the environment. Volunteer data collection is a way to fill this gap, especially for straightforward reporting of phenomena such as wildlife–vehicle collisions. After decades of environmental data collection by volunteers, the method has become increasingly trusted and verifiable. The chapter begins with a discussion of current advances in the data collection tools, processes, and applications in transportation and ecological studies. The volunteer data collection methods are then described for hand-held devices and data management approaches and needs. I discuss ways that these data can be used to support transportation decision-making to protect or restore ecosystems. Finally, to improve trust in the data, I propose here that past work on scientific workflows, formal data formatting and identification protocols, and a blockchain approach could be used to develop an overall approach formalizing volunteer data management and use in transportation decision-making. By building trust and verifiability into volunteer data collection, skeptical transportation agencies can be provided with a new and growing source of information and improve decision-making.